Hash function on list independant of order of items in it

Question

I want to have a dictionary that assigns a value to a set of integers.

For example key is [1 2 3] and value will have certain

Answer 1

I think your squaring idea is going in the right direction, but a poor choice of function. I'd try something more like the PRNG functions or just multiplication by a large prime, followed by XOR of all the resulting values.